1. Field of the Invention
The present invention relates to a system and method for locating a resource within a broadcasting environment. More specifically, the present invention relates to a system and method for enabling resources of one event, program, or transport stream within a broadcasting environment to be shared with resources of another event, program, or transport stream.
2. Description of the Conventional Art
A Digital Television (DTV) receiver receives data from multiple broadcasting entities. For instance, FIG. 1 illustrates a DTV receiver 11 that receives data from plural terrestrial broadcast stations 12, a cable system 13, a satellite system 14 and an Internet system 15.
Data is generally communicated to the receiver in the form of one or more transport streams. For instance, a feed from a terrestrial broadcast station 12 generally includes a single transport stream. However, a satellite or cable feed may contain a hundred or more transport streams.
FIG. 2 illustrates the content and structure of a conventional transport stream 21. As shown in FIG. 2, a conventional transport stream 21 generally includes a combination of one or more virtual channels 22, a single virtual channel 22 being capable of broadcasting a program. For instance, when broadcasting video programs, the virtual channel combines a video stream with one or more audio streams to provide multiple language capabilities, and one or more data streams to provide information which can be used to enhance the video program. Similarly, pure data programs can be broadcast having only data streams, each data stream representing a large number of data items to enable access by the receiver to tens of thousands of data items simultaneously.
A virtual channel 22 can therefore be described in terms of its component elementary streams 23 or its component events (not shown). Each elementary stream 23 within a virtual channel 22 includes one particular type of information, such as video information, audio information, or data. By contrast, unlike elementary streams 23, events generally include multiple types of information, such as a combination of video, audio and data. An event generally defines a portion of a program. For instance, an event might be a TV show. Events are often defined by criteria such as their duration.
The elementary streams 23 and events forming the virtual channels 22 may include data such as the HTML (xe2x80x9cHyperText Mark-up Languagexe2x80x9d) pages 24 shown in FIG. 2.
Moreover, the resources communicated to a DTV receiver potentially include virtual channels 22, elementary streams 23, events and/or individual data items 24.
It is sometimes useful to share the resources of related broadcasts that are received by a DTV receiver. For instance, using resources from within one channel or transport stream to supplement another channel or transport stream provides great flexibility for enhancing the viewing experience of the DTV viewer.
Conventionally, various schemes have been proposed for sharing the resources of related broadcasts without relying on bidirectional communication. However, as described in greater detail below, the conventional art fails to provide an efficient system for enabling resources to be shared between programs of separate channels within one or more transport streams, or even between events within separate programs.
Some conventional proposals for sharing the resources of related broadcasts are based on broadcasts which include embedded references to resources, which references are based on the absolute address of those resources or on some other fixed criteria for identifying the resources. Those proposals are therefore susceptible to some of the same problems experienced by direct addressing schemes applied to computer systems.
First, direct addressing schemes tend to be relatively inflexible with respect to relocation of resources since a change in the location of a resource frustrates fixed references to that resource previously embedded in other programs. For instance, if a resource is relocated, URLs embedded in programs under direct addressing schemes specify references to an outdated address for the resource.
Second, direct addressing schemes tend to be relatively inflexible with respect to replication of resources. Since each replicated copy of a resource requires an independent and unique address to avoid errors in a direct addressing scheme, an embedded reference to a fixed address cannot be used to achieve a hyperlink to any of the replicated copies. Therefore, the most convenient copy of a resource may not be available based on the fixed reference information embedded in the program.
The first and second problems are both evident when a single program is rebroadcast by multiple local affiliate stations or cable stations. Specifically, as demonstrated by FIG. 3, programs broadcast from a network broadcasting server 31 includes embedded references to resources of a local affiliate station addressed by call-sign (e.g., WXAB) or by channel (e.g., channel 17) of that local affiliate station. The program is retransmitted by local affiliates 32, WXAB and WXCD, and received by corresponding receivers 33, DTV#l and DTV#2, respectively. The receiver 33 DTV#1 corresponding to local affiliate WXAB has access to the transmit stream and channel specified in the embedded reference, and the receiver DTV#2 corresponding to local affiliate WXCD is without access to the transmit stream and channel specified in the embedded reference.
A third problem with conventional proposals resembling a direct addressing scheme is illustrated by FIG. 4. FIG. 4 demonstrates the difficulties experienced by an operator attempting to understand the reference specified by a reference embedded using the direct addressing scheme correspond to an actual address of a resource, it is difficult for an operator viewing those embedded references to recognize the underlying resource being referenced. Furthermore, due to the lack of meaningful pneumonic, typographical errors and the like are easily missed by an operator.
As an alternative to the proposals involving schemes resembling direct addressing, proposals have been offered for schemes based on embedded references to pneumonics corresponding to resources. These proposals more closely resemble conventional indirect addressing processes.
One such proposal provides specifications for TV and unidirectional HTTP (HyperText Transfer Protocol) schemes. In each specification, embedded references are used to describe resources to be shared. However, neither specification provides an identifier for locating the source of a resource described by an embedded reference. Rather, the proposal for the HTTP scheme seems to require the receiver to look at the header of every data item received from every channel to identify a match for an embedded URL, a slow and resource intensive task. Additionally, the teachings of each of these specifications are limited to channels, neither suggesting the use of references to other resources such as elementary streams, events and/or data.
Another conventional proposal that resembles an indirect addressing scheme involves embedding references to groups of interlinked Web pages into a TV broadcast, and mapping the embedded references into references that are meaningful in the context of DTV. More specifically, this proposal involves the use of translation information transmitted along with the TV broadcast for translating embedded references having an Internet format (e.g., xe2x80x9chttp:xe2x80x9d URLs) into a format that is meaningful in the context of DTV broadcasting (e.g., xe2x80x9cdtvxe2x80x9d or xe2x80x9catscxe2x80x9d URLs), so as to identify the location of corresponding resources within the TV broadcast. Such URL mappings could also be used more generally to translate URLs with arbitrary logical names for resources into URLs with direct addresses.
In order to locate the transport stream carrying an appropriate mapping table for translating an embedded URL, this proposal seems to require the entire mapping tables to be cached into memory by the DTV receivers. As such, the memory requirements and associated price of a conventional receiver adopting this proposed scheme would increase.
To compound this problem, conventional URL mappings used in this way require unnecessarily large mapping tables containing a great deal of redundant information. In most cases, all that is actually necessary is a mapping of the host name in the http URL to a corresponding event and elementary stream, not the full blown mapping described above. Furthermore, the mapping of the protocol can be inferred, and often the file path does not need to be mapped at all.
Moreover, the conventional art fails to provide an efficient system for enabling resources to be shared between programs of separate channels within one or more transport streams.
The present invention is directed to system that substantially obviates one or more of the problems experienced due to the above and other limitations and disadvantages of the related art.
Other and further objects, features and advantages of the present invention will be set forth in the description that follows, and in part will become apparent from the detailed description, or may be learned by practice of the invention.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention includes a system and method for enabling a referenced resource to be located within a broadcasting environment, where the method includes storing translation information into a receiver memory, identifying a location of additional translation information for the referenced resource based on the translation information stored in the receiver memory corresponding to that referenced resource, receiving the additional translation information from a transport stream identified by the transport information stored in the receiver memory for the referenced source, and locating the referenced resource based on the additional translation information received.
The process of storing the translation information in the receiver memory may involve storing less than all of the translation information communicated to the receiver, where the translation information stored in the receiver memory identifies a transport stream for the referenced resource. In addition, locating the referenced resource may include receiving further translating information from a channel identified by the additional translation information, and locating the referenced resource based on the further translation information received.
The system for enabling a referenced resource to be located within a broadcasting environment includes componentry capable of performing the above-mentioned tasks. A system and method for enabling a referenced resource to be located within a broadcasting environment, where the method includes storing translation information into a receiver memory, identifying a location of additional translation information for the referenced resource based on the translation information stored in the receiver memory corresponding to that referenced resource, receiving the additional translation information from a transport stream identified by the transport information stored in the receiver memory for the referenced source, and locating the referenced resource based on the additional translation information received.
The process of storing the translation information in the receiver memory may involve storing less than all of the translation information communicated to the receiver, where the translation information stored in the receiver memory identifies a transport stream for the referenced resource. In addition, locating the referenced resource may include receiving further translating information from a channel identified by the additional translation information, and locating the referenced resource based on the further translation information received.
The system for enabling a referenced resource to be located within a broadcasting environment includes componentry capable of performing the above-mentioned tasks.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. Thus, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of example only. Various changes and modifications that are within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In fact, other objects, features and characteristics of the present invention; methods, operation, and functions of the related elements of the structure; combinations of parts; and economies of manufacture will surely become apparent from the following detailed description of the preferred embodiments and accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in various figures.